Trouble removing yoke after a dive.

[Rudebob]

Has anyone encountered this? I use what I would consider normal hand pressure to tighten the yoke when putting on a fresh tank. However, at the end of the dive it takes all my strength and sometimes even tools to loosen the yoke. This just started happening over the last dozen or so dives. I have a couple hundred dives on this reg setup so it is not like I am unfamiliar with it. Yesterday the soft plastic knob finally stripped so I had to cut it off the threaded end allowing me to put a wrench on it to changes tanks. Does anyone know why this would be happening and how to avoid it? Also, can replacement knobs be found, a brief search did not reveal much out there.

Thanks, 'bob

 

[redacted]

Has anyone encountered this? I use what I would consider normal hand pressure to tighten the yoke when putting on a fresh tank. However, at the end of the dive it takes all my strength and sometimes even tools to loosen the yoke. This just started happening over the last dozen or so dives. I have a couple hundred dives on this reg setup so it is not like I am unfamiliar with it. Yesterday the soft plastic knob finally stripped so I had to cut it off the threaded end allowing me to put a wrench on it to changes tanks. Does anyone know why this would be happening and how to avoid it? Also, can replacement knobs be found, a brief search did not reveal much out there.

Thanks, 'bob

Sometimes high pressure in your SPG and HP hose can be very slow bleeding off which may re-pressurize the LP side of your rig after you release the purge. Try holding a purge down as you loosen the yoke screw. Many yoke screws are a standard threading and aftermarket replacement are readily available.

 

[dumpsterDiver]

Drill a hole in in, stick a bent nail in the hole and you are good for another 1000 dives. It is easy to drill brass.

 

[dmoore19]

Maybe stick the yoke in some vinegar and clean the threads?

 

[knotical]

Agree with awap and dmoore.
First thought is unrelieved pressure. Assuming the valve is fully off, and you're holding a purge button while loosening the yoke, there might be a reg failure mode that allows pressure to remain. Perhaps a reg service or at least inspection.
Second thought is threads. After cleaning threads, it shouldn't hurt to put a bit of lube on them, although I don't.
Third thought is - well, I don't have a third thought.

As for knobs, here are a couple of candidates:
Trident 1st Stage Yoke Knob 5/8 in.
Innovative Scuba Tank Valve Yoke Light Flashing at LeisurePro
But I’m willing to bet many service techs have some hanging around in their junk drawers.

 

[fisheater]

"Normal hand pressure" might contribute to the problem. "Finger tip" pressure is all you need or want.


Sent from my iPhone using Tapatalk

 

[spectrum]

You may need to replace the yoke screw assembly, still small money.

+1 to releasing the yoke immediately after a deep purge. The SPG hose is connected via a very small orifice and will re-pressurize and re-lock the cylinder connection.

Giving the screw and yoke some TLC with vinegar/toothbrush followed by a good rinse can give it a lighter touch.

Pete

 

[axxel57]

Yeah, first idea would be unrelieved pressure from the system.

If this is not the case and you dived this setup a couple of hundred dives, did you check that your yoke nut has hardly any play in the yoke.

I had that once when a yoke nut was getting more and more difficult to loosen after being pressurized, that the yoke nut had too much play in the yoke threads and jammed every time it got pressure.

It was a DIN to Yoke adapter, but who knows, maybe that can also happen to normal yokes.....

 

[Dr Dive]

Dr Dive sez:
Even minimal corrosion, a light patina of green, or oxidation is enough. Remember, metal also shrinks slightly when cold. We often set up on the dock or deck when everything is sun soaked, and hot. After dive, everything is chilled, including us. The combination of factors, with the hand tight squeeze can be enough. Lighten up on the tightening, remove the screw all the way, lube it with silicon or white grease, and reinsert. Should solve the problem.

 

[redacted]

Dr Dive sez:
Even minimal corrosion, a light patina of green, or oxidation is enough. Remember, metal also shrinks slightly when cold. We often set up on the dock or deck when everything is sun soaked, and hot. After dive, everything is chilled, including us. The combination of factors, with the hand tight squeeze can be enough. Lighten up on the tightening, remove the screw all the way, lube it with silicon or white grease, and reinsert. Should solve the problem.

What effect does temperature have when all metal parts are chrome plated brass?